1. The Field of the Invention
The present invention is in the field of commercial washing machines, and more particularly to methods for reducing waste of valuable resources, such as water, laundry chemicals (e.g., detergent, bleach, softener, etc.), fuels or other energy used to heat water, linens, etc.
2. The Relevant Technology
Commercial washing machines are routinely employed in various institutions that generate large volumes of linen (e.g., towels, bedding, clothing, etc.) to be laundered. Such commercial washing machines are of a size that is significantly larger (e.g., 60 lb or more capacity) than those employed in residential environments, and are configured differently so that they drain from the bottom of the machine. In contrast, residential washing machine models may drain from anywhere along the back of the machine, but include a siphon break that forces the water in the drain line to run up the wall above the top water level associated with the washing machine, before draining into the residential sewer line. The siphon break prevents water from being inadvertently siphoned, or pulled into the sewer line, so that it only drains from the washer when desired (e.g., pumped therefrom).
In addition, such commercial washing machines typically operate on a more sophisticated wash cycle, by which a portion of the wash water is added during sub cycles of the overall wash cycle. The chemicals for the overall wash cycle are also added sequentially (and automatically), rather than all at once. For example, such a washer may add a portion of the wash water (e.g., about 13 gallons for a 60 lb capacity washer) for a first sub cycle or portion of the overall wash cycle, the water may be at least partially drained, and new wash water added for a subsequent portion of the wash cycle, etc. Such washers may include 2, 3, or more such sub cycles in the overall wash cycle. In addition, the chemicals (e.g., detergent, bleach, softener, etc.) may typically be added automatically and sequentially, during the respective sub cycle portions of the overall wash cycle, as opposed to addition of all or most all chemicals at once (e.g., manually), as is the case in residential size washers. Such commercial washers are also typically programmable, so that the operator or technician may customize the various parameters associated with the various sub cycles of the overall wash cycle (e.g., cycle time, water added, chemicals added and how much, etc.).
Commercial washing machines typically include a solenoid valve within the drain line of the washing machine, which operates to selectively open and close a valve door in the drain line, allowing the wash water to be discharged, as needed.